. >> where were you when rebecca zahau died? >> i don't know what time rebecca zahau died. but i was at the hospital all night. >> in 2013, keith greer filed a lawsuit on behalf of the zahau family. he named dina as a defendant along with her twin sister, nina. there was also a third defendant -- the man who called 911. jonah's brother, adam shacknai. >> did you have anything to do with rebecca's death? >> absolutely not. >> greer disagreed. he pointed to those knots tied around rebecca's wrist and ankles. >> tying them was almost impossible. >> he believed whoever tied the knot had to be an expert, possibly a sailor. and adam shacknai worked on the mississippi river as a tugboat captain. >> he ties things off, he uses a figure 8, and then closes it with a single hitch or two. guess what knots are tied on both her legs and her hands? figure eights, tied off with a single hitch or two. >> sheriff's investigators had questioned adam extensively after rebecca's death. >> you didn't hold anything back from investigators? >> nothing. >> you helped them to the extent that you cou